Search results for "Botany"
showing 10 items of 4586 documents
The influence of bacteria-dominated diets on Daphnia magna somatic growth, reproduction, and lipid composition
2012
We explored how dietary bacteria affect the life history traits and biochemical composition of Daphnia magna, using three bacteria taxa with very different lipid composition. Our objectives were to (1) examine whether and how bacteria-dominated diets affect Daphnia survival, growth, and fecundity, (2) see whether bacteria-specific fatty acid (FA) biomarkers accrued in Daphnia lipids, and (3) explore the quantitative relationship between bacteria availability in Daphnia diets and the amounts of bacterial FA in their lipids. Daphnia were fed monospecific and mixed diets of heterotrophic (Micrococcus luteus) or methanotrophic bacteria (Methylomonas methanica and Methylosinus trichosporium) and…
Egg parasitoid attraction toward induced plant volatiles is disrupted by a non-host herbivore attacking above or belowground plant organs.
2014
Plants respond to insect oviposition by emission of oviposition-induced plant volatiles (OIPVs) which can recruit egg parasitoids of the attacking herbivore. To date, studies demonstrating egg parasitoid attraction to OIPVs have been carried out in tritrophic systems consisting of one species each of plant, herbivore host, and the associated egg parasitoid. Less attention has been given to plants experiencing multiple attacks by host and non-host herbivores that potentially could interfere with the recruitment of egg parasitoids as a result of modifications to the OIPV blend. Egg parasitoid attraction could also be influenced by the temporal dynamics of multiple infestations, when the same …
Binding analysis of Bacillus thuringiensis Cry1 proteins in the sugarcane borer, Diatraea saccharalis (Lepidoptera: Crambidae).
2015
Sugarcane borer (Diatraea saccharalis, F.) is an important corn pest in South America and United States. The aim of the present study was to analyze the susceptibility and binding interactions of three Cry1A proteins and Cry1Fa in a Brazilian D. saccharalis population. The results showed that Cry1Ab was the most active, followed by Cry1Ac, Cry1Fa and Cry1Aa. All Cry1-biotinylated proteins tested bound specifically to the D. saccharalis brush border membrane vesicles (BBMV). Heterologous competition assays showed shared binding sites for all Cry1A proteins and another one shared by Cry1Fa and Cry1Ab. Thus, pyramiding Cry1Aa/Cry1Ac and Cry1F proteins would be a recommended strategy for managi…
Exclusion of Saccharomyces kudriavzevii from a wine model system mediated by Saccharomyces cerevisiae.
2010
This study investigated the competition and potential hybrid generation between the species Saccharomyces cerevisiae and S. kudriavzevii in a wine-model environment. Our main goal was to understand why S. kudriavzevii has not been found in wine fermentations whilst their hybrids are present. Auxotrophic mutants (Ura(-) and Lys(-)) were used to favour the selection of hybrids and to specifically differentiate the two species in mixed fermentations carried out at different temperatures (17 °C, 24 °C and 31 °C). Both yeasts showed a reduction in their maximum specific growth rates in mixed fermentations, indicating a clear antagonistic effect between the two microorganisms. Temperature played …
Dioecious species and arbuscular mycorrhizal symbioses: the case of Antennaria dioica.
2013
Sex-specific interactions with herbivores and pollinators have been observed in female and male plants of dioecious species. However, only a limited number of studies have revised sex-specific patterns in mycorrhizal symbiosis. To test whether female and male plants of Antennaria dioica differ in their relationship with arbuscular mycorrhizal (AM) fungi, we examined the temporal and spatial variation in AM fungi in female, male and non-reproductive A. dioica plants in three natural populations in Finland during flowering and after seed production. Our results are consistent with previous studies both under greenhouse and field conditions with the same species showing differences in AM colon…
Contribution à l'étude des « goûts de lumière » dans le vin de champagne. II. Influence de la lumière sur le potentiel d'oxydoreduction. Corrélation …
1978
<p style="text-align: justify;">Les auteurs déterminent les potentiels d'oxydoréduction de nombreux vins de champagne avant et après la prise de mousse. Ils précisent la relation, par éclairement de vins dégorgés et non dégorgés, entre l'apparition de « goût de lumière » et le potentiel d'oxydoréduction. Ils donnent les longueurs d'onde responsables des « goûts de lumière ».</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">The oxydoreduction potentials are determined for a number of wines of champagne before and after the second prise de mousse fermentation. By illuminating disgorged and non disgorged wines, the authors of this article …
Nitric oxide and cortico-striato-pallidal motor circuitry: Quantitative EEG analysis of surface and depth recordings
2002
Rats treated with i.p. 7-NI showed a significant increase in cortical higher frequency EEG bands, associated with a corresponding and significant decrease in delta band activity. In the striatum, reduced levels of NO induced an increase in the low frequency band, and a decrease at higher frequencies. Pallidal depth recordings showed modifications to several frequency bands, similar to those found in the cortex. Although 7-NI was administered at increasing doses (from 40 to 70 mg kg–1), it was not possible to demonstrate a relationship between modified band activities and the dose of 7-NI. As suggested indirectly by the quantitative EEG data reported in this study, NO plays a fundamental rol…
Different species and symbiotic genotypes of field rhizobia can nodulate Phaseolus vulgaris in Tunisian soils.
2002
Abstract A collection of 160 isolates of rhizobia nodulating Phaseolus vulgaris in three geographical regions in Tunisia was characterized by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-amplified 16S rDNA, nifH and nodC genes. Nine groups of rhizobia were delineated: Rhizobium gallicum biovar (bv.) gallicum, Rhizobium leguminosarum bv. phaseoli and bv. viciae, Rhizobium etli bv. phaseoli, Rhizobium giardinii bv. giardinii, and four groups related to species of the genus Sinorhizobium, Sinorhizobium meliloti, Sinorhizobium medicae and Sinorhizobium fredii. The most abundant rhizobial species were R. gallicum, R. etli, and R. leguminosarum encompassing…
Seducin, male sex pheromone of the cockroachNauphoeta cinerea: Isolation, identification, and bioassay.
1990
The male sex pheromone of the cockroachNauphoeta cinerea was isolated from adult sternal glands and identified by gas chromatography-mass spectrometry. This pheromone, which attracts females from a distance, is a multicomponent blend. It is composed principally of three compounds: 3-hydroxy-2-butanone (acetoin), 2-methylthiazolidine, and 4-ethyl-2-meth-oxyphenol. A mixture of synthetic compounds in a ratio of 4∶4∶1 (2700 ng) elicits maximal response and short latency of response by receptive females, similar to that induced by male sternal gland extracts. Tested separately, each compound induces a positive response, but the moving times spent by females are generally longer than with the mi…
"It's like being stuck on an unsafe and unpredictable rollercoaster": Experiencing substance use problems in a partner.
2020
Living with a partner with substance abuse problems may induce strains in an individual’s everyday life, including poor health, disrupted family life, and social isolation; this may lead to dropping out of education or work, a lack of safety and support, and facing various dilemmas and stigma.Aim:The purpose of this study was to explore these partners’ everyday life experiences, including their parental roles.Method:A qualitative design comprising qualitative interviews with ten partners and ex-partners was performed, and a thematic analysis was used.Results:The findings demonstrated that sharing their lives, including parenthood, with a partner with substance use problems affected every as…